[R] DRC package: Weibull W1.3 and W2.3 - where is the difference?

[Ecotox]

Hi!

I am trying to use a 3-parametric Weibull model. I used mselect to find the
best-fit model which was W1.3 in one and W2.3 in another case. When
searching the internet for formulas, I only find a formula for W1.3, which
is: 

 f(x) = 0 + (d-0)\exp(-\exp(b(\log(x)-e)))

But what is the formula for W2.3? And why is the first term written 0+(d-0)
and not just d? For me this doesn't make sense...

Anyone who can help?

Thnaks in advance!

Ecotox



--
View this message in context: http://r.789695.n4.nabble.com/DRC-package-Weibull-W1-3-and-W2-3-where-is-the-difference-tp4667690.html
Sent from the R help mailing list archive at Nabble.com.